Pump



Jan. 12, 1937.

J. O. MCMILLAN PUMP Original Filed March 27, 1929 4 Sheets- Sheet 2 Jan. 12, 1937. .4. o. McMlLLAN PUMP Original Filed March 27, 1929 4 Sheets-Sheet 4 mm m 4 W M L O O 9 0 Z 0 Z 2 W 2 o 2 2 2 M w k u J I s I e M. m l m w i a 2 m 2 o 87 6 8 201-. 4 a H 1 s o o o z z 0 H3 5 1 1 Z 1 I x. C N u fl| 1 U hfiau- R NA 1 Z /8 a o o 1 1 w J m atented Jan. 12, 1937 FATENT QFFHE Refiled for abandoned application Serial No.

350,264, March 27, 1929. This application August 15, 1934, Serial No. 739,987

14 Claims.

This invention relates to pneumatic liquid pumping systems of the type that is automatically controlled by the opening and closing of one or more faucets. It is designed especially for supplying fresh water to homes and industrial plants from a well or other source of water nearby, and while in its preferred form it is of the closed type for use in a closed water system, it may also be used in open pumping, and of course, it may be employed in pumping liquids other than water.

It is the purpose of my invention to supply water fresh and aerated from the well or other source of supply, without the use of a storage tank; the well or source of supply being the only reservoir required. My mechanism may be employed for pumping liquids whether hot or cold.

Wells of great depth have not been pumped successfully with pneumatic displacement pumps because of the high fluid pressure necessary to elevate the liquid in single stage pumping, and further because of the inability of the valves and mechanism to operate and endure under the high pressure required. Moreover, the complications and lack of compactness in former pneumatic pumps have not fitted them for multiple stage pumping, with the result that they have not been applied successfully to wells having a depth of over 400 or 500 feet.

My present pump overcomes these difficulties, and this has been demonstrated in actual practice, and the design of the novel pump is such that it is simple, compact and very durable. Furthermore, it may be readily incorporated in a multi-stage pumping system whenever this is necessary or desirable.

The improved pump is of the single cylinder type adapted to be submerged under water, and to elevate liquid by compressed air, natural gas, or any other suitable fluid agent under pressure. When the pump barrel is submerged under four feet of water, it may be filled in about two seconds, and as it only has a single cylinder, the discharge is intermittent.

To obtain a steady continuous flow at the faucet, I employ the well known pump air chamber or equalizer to flow the liquid during the filling stroke of the pump.

The present pump is especially designed for adapting it for various hook-up installations, such as boosting city water in tall buildings, multiple stage pumping and doublel cylinder pumping, where a larger volume of liquid with a steady continuous flow is desired. In such installations, the discharge of a lower pump will be connected to the intake of the pump unit above. If such an installation is to be employed as a double cylinder pump, both units will be submerged in the water of the well for instance, the lower pump discharging its contents into and through the upper pump, while the latter is refilling. On the other hand, while the lower pump is refilling, the upper one may be discharging into the common outlet pipe used for both units. In this way, the volume delivered may be increased and the flow may be continuous without the use of a pump air chamber or equalizer.

The majority of water wells contain sand and 15 grit, and so far as I am aware, all pneumatic pumps of the displacement type which have been used heretofore, have given more or less trouble wherever any appreciable amount of sand has been encountered, and this has brought about blow overs or stalling of the pump. With the improved mechanism, I have pumped large amounts of sand mixed with the water without any apparent effect on the pump. I accomplish this result partly by the use of a control valve head which does not depend for its action upon the fluid pressure or the liquid under pressure in the pump cylinder, and I also use specially designed check valves that are yieldable to sand, as well as strainer means properly placed to keep out foreign matter.

The foregoing sets forth some of the main objects of this invention, but I have other objects in view which will appear as the description proceeds. The construction and operation of the pump will now be described in connection with the accompanying drawings, in which Fig. 1 is an elevation of my improved pumping system, showing a portion of the same arranged in a well, and the latter in vertical section.

Fig. 2 is an enlarged vertical sectional View of the main portion of the pump, taken on line 22 of Fig. 3.

Fig. 3 is a similar view taken on line 3-3 of Fig. 2.

Fig. 4 is a further enlarged vertical sectional view of a detail.

Fig. 5 is an elevation partly in vertical section, showing a plurality of my improved pumping 50 units and the manner of connecting them for use in multi-stage pumping.

Fig. 6 is an elevation of a pair of the units hooked up for double cylinder pumping purposes.

Fig. '7 is an elevation partly in vertical section 55 of one of the units when used as a booster installation.

In the embodiment of the invention illustrated in Figs. 1 to 4 inclusive, l designates a pump cylinder whch may be formed from a length of suitable tubing, the ends of which enter recesses 2 in the head or control member 3, and the foot valve 'i. Suitable packing rings 5 are located in these recesses, and the head and foot members are held in engagement with the tube l, by a hollow or tubular element 6. This element includes a length of pipe '5, having a threaded connection at its upper end with the head member, and communicating with a chamber 8 arranged in that member. The lower end of the pipe has a threaded connection with the casing 9 of the liquid discharge valve iii, which in turn is joined by screw threads to a nipple ii that extends through the bore E2 of the foot member, and is provided at its outer end with a hollow nut 53 having a grounded joint at [4 to make a liquid tight connection. A threaded plug 15 is fitted into this nut and when double cylinder pumping is to be employed, this plug may be removed so that the nut may be connected to a lower pumping unit in a manner hereinafter explained. At this time, it may be stated that the plug may be substituted by a pedestal or standard l6, (see Fig. 1), if the cylinder is to rest at the bottom of a well for instance.

It will be obvious that when the nut i3 is detached from the nipple, the parts may be readily dismantled.

Water from the well or other source of supply enters the chamber ll of the cylinder through the foot member, and to this end, the latter is provided with a number of ports l8, the lower or outer ends of which are obstructed by a perforated shield or screen l9, preferably of frustoconical shape, and held in place by the nut l3. The ports [8 open through the upper face of the foot member, and they cooperate with a common valve ring 28, which may rise and fall, due to liquid pressures on opposite sides thereof, and which is guided by a tubular element or guide 2i that, at its lower end, has a threaded connection with the foot member, and at its upper end has an overhanging disk 22 functioning to limit the upward movement of the valve ring.

Lquid from the cylinder chamber is discharged into the pipe 7 by way of the ports 23 which are also controlled by a common valve ring 24, but as this outlet valve forms the subject matter of my Patent No. 1,776,266, dated Sept. 23, 1930, it is believed unnecessary to further describe the same here.

From the foregoing, it will be obvious that the liquid enters the cylinder through the valve at the foot of the same, and is then discharged by way of the pipe I into the control head, and from the latter, it will travel through the service pipe 25. This pipe communicates with the pipe 1 by way of the passageways 8 and 27, positioned in the control head.

As before stated, the liquid is forced from the cylinder by some suitable pressure medium such as compressed air, and if air is used, for this purpose, it may be compressed into a reservoir or tank 28 (Fig. 1) by means of a suitable compressor 29, and I prefer to use in the piping 30 between the compressor and tank, an unloading checkvalve 3 l which will automatically release the pressure from the compressor when the latter stops, so that the motor driving the compressor will not be forced to buck any pressure when the compressor is again started.

An air conducting pipe- 32 places the compressed air reservoir in communication with a chamber 33 in the control head, and a strainer 34 is located in this pipe to prevent deleterious matter from the compressing mechanism, passing into the control head. Referring particularly now to the latter, it may be seen from Fig. 4, that it includes a diaphragm 35, clamped in place by a cap 36 secured by screws or the like 3?. This diaphragm acts to shift some of the control valves in a manner now to be described. For this purpose, a horizontally reciprocating rod or stem 38 passes through the diaphragm and is secured to the latter by a nut 39 which also forms a guide for a coiled spring 49 that bears at one end against the diaphragm, and at its other end against the cap, and tends to shift the diaphragm toward the left.

One end portion of the stem is bored out to provide a passageway ii that communicates by a port @2 in the valve stem with the chamber 33, whereby live air from that chamber continually flows through the stem and into the cap chamber 5%, for the purpose hereinafter described. The port in the stem is protected by a loose cylindrical sleeve '55, and there is sufficient clearance between the stem and sleeve to allow the air to flow.

Chamber 33 communicates at proper times with a chamber 46 by way of the cylindrical port 4?, through which an angular or hexagonal guide 48 on the stem extends, and this port is preferably arranged in a threaded collar 39 that is attached to a fixed portion of the control head, and may be removed when the valves are to be dismantled.

From Fig. i it may be seen that the left end of the valve stem is also threaded as shown at 50, and mounted on this portion of the stem are oppositely facing valves 5! and 52, the former functioning to close the air intake port 57 at certain times. The other valve 52 controls an air exhaust port 63 in the head, through which air may travel to an exhaust chamber 53, and this port also acts as a guide for a member 55 that is threaded on the end 56 of the stem and functions to hold the valves 52 and 52 in proper positions. Said rod or stem 36 and associated parts Y constitute a mounting common to valves 5! and 52 and diaphragm 35.

Air exhausts from chamber 54 to atmosphere, through a pipe 51 that extends above the water line when the apparatus is used for well pumping or the like.

As part of the control head,'I have what I term a master valve 58 functioning to control a master port t9 that leads to an exhaust tube 60 projecting upwardly into the chamber 54. This tube is of relatively small diameter, and as it projects upwardly in its chamber, it is obvious that deleterious matter entering the chamber 54 will be prevented by the tube from reaching the master port or interfere with the operation of the master valve. In other words, I employ this structure to protect the master valve and the port which it controls. This valve is of special construction, and it includes a cup or cap 61 secured to the under side of the control head by any suitable means such as screws 52, and projecting into the cylinder chamber.

The screws hold the cup against the control head so tight as to prevent any communication. between the master valve chamber 53 and the cylinder chamber. One side of the cup has a threaded opening in which a threaded nipple 84 is fitted, and a rock shaft 55 extends through this nipple. The shaft has a conical face, and the nipple a similar shaped ground surface at its inner end, so as to form a ground joint at 56 to prevent the escape of air along the shaft. As a further insurance to this end, a packing washer 61 surrounds the shaft and is held in abutting relation with the nipple by means of an upper lever 68, fixed to the outer end of the shaft by any suitable means such as a pin 69.

The inner end of the rock shaft has a threaded opening with its axis intersecting the axis of the shaft, and this opening receives a threaded extension 18 on the lower end of a pin 1|, which carries at its upper end the master valve. In order that this valve may last indefinitely, I prefer to make the same in the form-of a rubber ring or cylinder which may rotate on the pin, whereby a multiplicity of surfaces of the same may be presented to the end of the master port.

At this point it may be observed that a passageway 12 constantly places the chamber 53 in communication with the cap chamber 44, whereby when the master valve is open, live air from the chamber 33 may bleed through the valve stem into the cap chamber 44, and from the latter passed by the way of the chamber 63 into the air exhaust chamber 54. On the other hand, when the master valve is closing its port, any live air leaking through the bleed passageway will function to build up a pressure in the chamber 44 at the right hand side of the diaphragm to assist the latter in throwing the valves 5| and 52 toward the left.

A passageway 13 constantly places the compartment 46 in communication with the cylinder chamber l1, and at the point of communication between the passageway and the chamber IT, a screen 14 is arranged to prevent deleterious matter from travelling with the air from compartment 48 to the chamber H, and vice versa.

An actuating member consisting of a float 15 of annular form is arranged in the pumping chamber and rises and falls with the liquid in the latter, while being guided by the pipe 1. At the upper end of its stroke, the float strikes the upper lever 58 for closing the master valve 58. When the liquid falls in chamber H, the float contacts with a roller 16 mounted upon one end of a lower lever 11. The latter is pivotally mounted at 18 upon a clamping collar (9 arranged on the lower end of the pipe 1, and this lower lever has a counter-balancing weight 80. As the upper and lower levers are connected together by a pull rod 8 I, the weight 80 will counterbalance both levers 68 and 11, as well as the master valve 58. Some suitable means, such as a coiled spring 82, is employed for snapping the lever 11 into either one of its extreme positions of movement, and the coil spring has its ends connected to the lever and to the clamping collar at such points that the lever in moving will shift the spring to one side or the other of the pivot point 18. Obviously, when the float is depressing the lever as soon as the spring 82 is moved past the pivoting point 18, the spring will function to snap the lever into its lowermost position.

Before describing the operation of the pump, it might be observed that the liquid discharge line which has the faucet or faucets 83 connected thereto, is provided at the top of the well with an air chamber or equalizing chamber 84.

As the pump is intermittent in action, this chamber will receive some of the pumped liquid on the pressure impulse of the pump, and then, while the chamber I1 is refilling, the faucet or faucets will be fed from the liquid in the equalizing chamber 84.

It may also be observed at this point that the diaphragm 35 and the means for actuating the same forms a differential pressure or an oscillating motor, and in some of the claims this mechanism will be referred to by one or the other of those terms.

Operation Assuming the cylinder I to be submerged in the liquid to be pumped, and just ready to fill, the liquid enters the cylinder through strainer l9 and ports I8, by lifting valve ring 20. As the liquid rises in the cylinder, the float 15 will ascend until it comes in contact with the upper lever 68. As the float continues to rise, it will lift this lever and cause the master valve 58 to close the port 59. During this procedure, live air is constantly entering the chamber 33 from the pipe 32, and is flowing through the passageways 4| and 12 to the chamber 63, and in acting on the diaphragm 35, holds the control valves 5| and 52 in their extreme right position. However, as soon as the master valve closes the port 59, the live air bleeding through passageway 4| can no longer escape to atmosphere through the chamber 54, and consequently, the pressure will build up through the cap chamber 44, and in this way, the pressure on opposite sides of the diaphragm will be equalized. When this happens, the live air in port 41 will act upon the air inlet valve 5|, and snap the control valves and their stem 38 toward the left, whereby chambers 33 and 46 will be placed in communication, and chamber 48 will be cut off from communication with chamber 54. The snapping action of the valve stem is assisted by the diaphragm spring 40, but said spring is not absolutely essential to the operation, for I have found in practice that the oscillating motor will function without the same.

When the parts have been thrown toward the left, the live air will pass from pipe 32 through 33, 41, 46, I3 and 14, into the cylinder l1, and in the latter it will function to force the liquid through the ports 23 of the water outlet valve l0, and into the pipe I. The liquid will flow then through chamber 8 and passageway 21, into the service line 25, and will finally reach the equalizing chamber 84, and some of the pumped liquid will occupy this chamber and function as a reserve when the cylinder I1 is to be refilled.

As the cylinder I1 is emptying, the float will descend, and on approaching the lower limit of its movement, will contact with the roller 16, and depress the lower lever 11 to the point where the snap spring 82 will come into action and snap the lower lever into its extreme lower position. As the lever is connected to the pull rod 8|, it will pull that rod and cause the upper lever 68, to tilt the master valve 58 into open position, and as the passageway 12 and the bore of the tube 50 are of larger area than the bleed passageway 4|, the live air on the left hand side of the diaphragm 35 will now snap the valves 5| and 52 toward the right, so that live air will now be cut off from chamber 45 and the cylinder chamber l1, and the air from the latter chamber will exhaust through 74, 13, 48, 53 and 54, as the chamber l'l refills under hydrostatic pressure. While the chamber is refilling, of course, live air bleeds through the passageways 4|, 12 and 60, and to the atmosphere through the pipe 51.

Obviously, due to the spring 82, the upper and lower levers 68 and T! will remain in their lower positions until the top of the float 15 again strikes the lever 60, and upon lifting the latter, the master valve 58 will be again closed, and the cycle will be repeated.

I have heretofore mentioned that my present pump will not alone force water, but the construction is such that the water will be aerated. To this purpose, the pipe 1 is provided above the lever 71 with a small port 86 through which air under pressure may enter the pipe 1 from the chamber ll, each time the cylinder is being emptied of liquid, and the air so admitted to the pipe '3 will not alone aerate the water, but some of this air will reach the equalizing chamber 84, so that the latter will always perform its desired function.

Because of the chemical actions of many waters, I prefer to employ Monel metal in all strainers, pins and screens, and in the brass castings forming the head and foot members, as well as the brass tube I, I. deem it best to use brass having a high percentage of copper.

I also prefer to use oil resisting rubber valves for the parts 5|, 52 and 58, since there are many air compressors which throw oil that is mixed with the air, and as this oil comes in contact with rubber valves, they will swell and soften unless oil resisting rubber is used.

My improved pump has been so designed that the cylinders may form superposed units for multi-stage pumping installations, as shown in Fig. 5. This arrangement is to be used in deep wells or wherever it is necessary to elevate liquid from a great depth under relatively low air pressure. As shown in this figure, one pumping unit I is submerged in the liquid in the bottom of the well, and a second unit i0! is placed several hundred feet above the submerged pump, and so on.

Pump unit l00 fills by hydrostatic pressure through strainer I02, and inlet check valve I00. The compressed air from pipe I is led to the air inlet chamber of both pump units, and it elevates the liquid through pipe "30, from the control head of the lower unit into a special shell I07, fitted to the lower end of the upper unit. The water, after passing through the shell I00 enters the ports I08 of the foot valve of the upper unit, and raises the valve ring I09 of that unit, and thus fills the cylinder of the upper unit. As each unit is constructed similar to the unit shown in Figs. 2 and 3, it will be apparent that as soon as live air is admitted to the cylinder lill, the Water will be forced through the outlet valve H0 into the service line Ill, which conveys the pumped liquid to the point of disposal. Of course, if a third unit is placed in the service line above the unit i0l, a similar action will take place in the third unit for lifting the liquid higher.

In a multi-stage pumping installation of this character, the air exhaust chamber of each control head may be provided with air exhaust pipes H2, each of which may have a mufiler H3 for silencing purposes. I

It will be apparent to those skilled in the art that in a structure of this character, each upper pumping unit is dependent upon the supply of liquid from a lower unit.

For double pumping purposes, two or more units may be submerged in the well, or other source of supply, as illustrated in Fig. 6. Referring to this view, it will be observed that both units 200, Ml are submerged in the liquid to be pumped, and each unit is of identically the structure shown in Figs. 2 and 3. Consequently, the liquid may enter both cylinders by way of the foot valves 202, but the liquid outlet pipe 203 of the lower unit is connected by the nut 204 to a nipple of the upper unit that is similar to the nipple ll. of the structure shown in Figs. 2 and 3. Consequently, liquid pumped by the lower unit will enter the liquid discharge pipe 205 of the upper unit, and at the same time liquid from the upper cylinder may enter the same pipe through the discharge valve of the upper'unit which corresponds with the valve I0 in Figs. 2 and 3.

In this form of the invention, the live air is led to both units by means of a common supply pipe 206, and the air is exhausted from both units by a common exhaust pipe 201, preferably provided with a mufller 208 arranged above the water line. course leads the water to the service line.

Instead of two units in such an installation, of course a greater number may be employed if desired, and in connecting up these units, the plug 209 is removed from the lower end of each upper unit, and the nut 204 of that unit is then connected to the water outlet pipe 203 of the unit immediately below.

In the operation of this form of pump, the water fills both units through the strainers l l0 and the foot valves 202, and as each pump operates independently of the other, neither pump will interfere with the operation of 'the other. This makes it impossible for the valves to center and cause loss of air. Furthermore, it makes it impossible for the pump to race, a defect which is present in a two-cylinder pumphaving a common control valve head.

Under some circumstances, it may be desirable to use my improvements for boosting water from a city water main or service main to a higher level, as in tall buildings, without submerging the pump. This may be accomplished as shown in Fig. 7. Here one of my improved units 300 is provided at its lower end with a connecting shell 30! which joins a city or other service main 302 to the foot valve 304 of the unit.

Assuming for example, that the pressure in the service main is sufiicient to raise the water 100 feet, the pumping unit may be arranged at this elevation. Under such circumstances, the water from the. main will flow through the strainer 305 and ports 306, past the inlet check valve 301, and into the cylinder. As this unit is like the unit shown in Figs. 2 and 3, of course, when the float rises with the water, to the point where the master valve will be thrown, live air will enter the unit through the pipe 308, and will force the water through the outlet valve 309 into the discharge pipe 3I0. When air is admitted to the cylinder and water is discharging from the valve 309, the check valve 301 will be forced to its seat, so that the pumped liquid will have to discharge by way of pipe 3I0, and thus be raised to a higher elevation.

Manifestly, aboosting unit may be employed at any elevation desired, and any number of these units may be inserted in the pipe line extending for instance, to the top of a very tall building. I

In this installation, the pipe 205 of To pump fresh water from a well under pressure, and control the operation of the pump by opening and closing one or more faucets, is broadly a matter of prior art. But the systems which have been in use, have given considerable 1 trouble, in that they have stalled or become inoperative, due to the misoperations of the pneumatic controlling devices employed, causing the pressure air to blow out with the water, and losing pressure also through the exhaust valve, due to centering, and complete stalling of the pump, owing to the inlet valve failing to open.

These disadvantages are caused, primarily, by two distinct elements, namely; sand and gritty matter in the water, and the slow leaky discharge of water from the pump, causing a slow and impositive movement of the air valve mechanism, from air admission position, to air exhaust position, and vice versa. I have overcome these difliculties by the mechanism described above.

In pumps of this kind, it has been customary to connect a tube to one side of the diaphragm leading to the lower end of the pump, and provided with a valve actuated by the weight of the float, and in which the air or water under pressure. enters the tube, and is conveyed to one side of the diaphragm to shift the main air valves. This principle of operation is objectionable, in that sand and other solid matter often enters the tube and diaphragm chamber, clogging the passageway and making the pump inoperative. This principle is also objectionable in that it brings about more complications of design than the principle of operation which I have devised.

In my improved pump, I use the master valve in the head or top of the pump, and seal the compartment of this valve from the pump chamber, so that sand and other solid matter cannot reach this main control valve of the system. Furthermore, the live air used in forcing the water from the pump cylinder does not flow past this master valve. Under trial test, when the cylinder was submerged four feet under water, it filled in a period of about two seconds.

When the master valve is closed by the float or similar means, air pressure independently of the pressure in the pump cylinder builds up on one side of the diaphragm 35, equal to the pressure on the other side, by way of the bleed passageway 4|. As before stated, this action causes the exhaust valve 52 to close, and the inlet valve 5! to open, due to the inlet valve being seated against pressure, and the pressure on both sides of the diaphragm being equal.

So far as I am aware, there are no pumps of this type which have incorporated in them the special feature of the by-pass check valve 10, and foot valve 4. This is so made in order to permit a simple installation of two pumps (Fig. 5), as in stage pumping or double cylinder pumping (Fig. 6). The fluid or discharge line of the lower pump being connected to the upper pump and discharging through the same without disturbing the upper pump, and without having to run the discharge line alongside the upper pump. This arrangement of discharge pipe makes a neater and more compact installation. There are other reasons for the use of a by-pass check valve and foot valve, as set forth above.

From the foregoing it is believed that the construction, operation and advantages of the invention may be readily understood, and I am aware that various changes may be made in the details disclosed without departing from the spirit of the invention, as expressed in the claims,

This application is a duplicate substitute for applicants application Serial Number 350,264.

What I claim and desire to secure by Letters Patent is:

1. A pump of the character described, including a cylinder having liquid inlet and outlet means, an oscillating motor, valves operable by the motor controlling the admission of a pressure fluid to the cylinder, a passage for the ex haust of pressure fluid, said motor including a flexible membrane having a chamber at one side thereof, a mounting common to said valves and said diaphragm, a passageway placing said chamber in communication with the atmosphere through said passage, a tiltable master valve alternately opening and closing said passageway, and means controlled by the rise and fall of liquid in the cylinder for actuating said master valve.

2. In a pump of the character described, a cylinder, means for admitting liquid into the cylinder and for dischaging liquid from the cylinder, means including an oscillating motor for admitting a pressure-fluid to the cylinder and for discharging the pressure fluid from the cylinder, an exhaust chamber for pressure fluid, means including a master valve and a bleeding passage extending from said motor to said chamber, said master valve including a stem having a head to alternately open and close said passage, and means actuated by the rise and fall of liquid in the cylinder for operating said master valve.

3. In a pneumatic displacement pump, a pumping chamber, means including diiferential motor actuated valves for admitting a pressure fluid to said chamber and for discharging said fluid from the chamber, a depending valve casing within the pumping chamber, a master valve chamber in the casing isolated from the pumping chamber, a rock shaft extending through a wall of the master valve casing into the pumping chamber, a master valve actuated by said shaft in said casing and chamber to alternately open and close to enable bleeding of the pressure fluid through the said means, and means in the pumping chamber for actuating the rock shaft, due to the rise and fall of the liquid in the pumping chamber.

4. In a pneumatic displacement pump, a pumping chamber, means including differential pressure motor actuated valves for admitting a pressure fluid to the pumping chamber and for releasing such pressure fluid from the chamber, a valve casing within the pumping chamber, a master valve chamber in said casing in bleeding communication with said motor and the exhaust line for the pressure fluid and isolated from the pumping chamber, a rock shaft extending through a wall of the master valve casing into the pumping chamber, means cooperating with said shaft for preventing any leakage along the shaft from one chamber to the other, a master valve in the master valve chamber operatively connected to said shaft to alternately establish and out 01f bleeding of the differential pressure motor, and means functioning due to the rise and fall of liquid in the cylinder for rocking said shaft.

5. A pump of the character described, including a cylinder having liquid inlet and outlet means, an oscillating motor, valves operable by said motor controlling the admission of pressure fluid to the cylinder, said motor comprising a flexible diaphragm having a chamber at one side thereof, a conduit for discharging pressure fluid from the cylinder, a passageway placing said chamber in communication with said conduit, a

master 'valve controlling said passageway, means controlled by the rise and fall of the liquid in the cylinder for actuating said master valve, and means for protecting the master valve from the liquid.

6. A pump of the character described, including a cylinder having liquid inlet and outlet means, an oscillating motor, valves operable by said motor controlling the admission of a pressure fluid to the cylinder, a master valve controlling the. oscillating motor, and means controlled by the rise and fall of liquid in the cylinder for actuating said master valve, said master valve being arranged in a chamber isolated from the interior of the cylinder, and means for protecting the master valve from the liquid.

'7. In a pump'having a pumping chamber and pneumatic displacement means for admitting liquid into said chamber and forcing liquid therefrom, said pneumatic displacement means including a control head having a passage communicating with the pump chamber so that pressure fluid may be admitted to the pump chamber and exhausted therefrom, a pressure fluid inlet chamber, a port between the latter chamber and said passage, a pressure fluid exhaust chamber, a port between the latter chamber and passage, a diaphragm in said inlet chamber, valve means to close one port as the other port is opened and vice versa, an element carrying said valve means operable by the diaphragm, a bleed chamber on the opposite side of the diaphragm to the pressure fluid inlet chamber, a bleed passage in the element establishing communication between the pressure fluid inlet chamber and bleed chamber, a passage from the bleed chamber to the pressure fluid exhaust chamber, a master valve in and controlling the latter passage and means controlled by the rise and fall of the liquid in the cylinder to actuate said master valve.

8. In a pump having a pumping chamber and pneumatic displacement means for admitting liquid into said chamber and forcing liquid therefrom, said pneumatic displacement means including a control head having a passage communicating with the pump chamber so that pressure fluid may be admitted to the pump chamber and exhausted therefrom, a pressure fluid inlet chamber, a port between the latter chamber and passage, a pressure fluid exhaust chamber, a port between the latter chamber and passage, a diaphragm in said inlet chamber, valve means to close one port as the other is opened and vice versa, said valve means and ports being located between the pressure fluid inlet chamber and pressure fluid exhaust chamber, an element carrying said valve means operable by the diaphragm, a bleed chamber on the opposite side of the diaphragm to the pressure fluid inlet chamber, a bleed passage in the element establishing communication between the pressure fluid inlet chamber and bleed chamber, a passage extending substantially transversely from one side of the control head to the other side thereof establishing communication between the bleed chamber and the pressure fluid exhaust chamber, and a master valve in and controlling the latter passage, and means controlled by the rise and fall of the liquid in the cylinder to actuate said master valve.

9. In a pump having a pumping chamber and pneumatic displacement means for admitting liquid into said chamber and forcing liquid therefrom, said pneumatic displacement means including a control head having a passage c0m municating with the pump chamber so that pressure fluid may be admitted to the pump chamber and exhausted therefrom, a pressure fluid inlet chamber, a port between the latter chamber and said passage, a pressure fluid exhaust chamber, a port between the latter chamber and passage, a diaphragm in said inlet chamber, valve means to close one port as the other port is opened and vice versa, an element carrying said valve means operable by the diaphragm, a removable cap on one side of said control head providing a bleed chamber, a bleed passage in the element establishing communication between the pressure fluid inlet chamber and bleed chamber, a passage from the bleed chamber to the pressure fluid exhaust chamber including a chamber extending upwardly from the lower end of the control head, a cap attached to the control head depending therefrom in line with the last mentioned chamber, a master valve in the last mentioned chamber and cap and controlling the last mentioned passage, and means controlled by the rise and fall of the liquid in the cylinder to actuate said master valve.

10. In a pump having a pumping chamber and pneumatic displacement means for admitting liquid into said chamber and forcing liquid therefrom, said pneumatic displacement means including a control head having a passage communicating with the pump chamber so that pressure fluid may be admitted to the pump chamber and exhausted therefrom, a pressure fluid inlet chamber, a port between the latter chamber and said passage, a pressure fluid exhaust chamber, a port between the latter chamber and passage, a diaphragm in said inlet chamber, valve means to close one port as the other port is opened and vice versa, an element carrying said valve means operable by the diaphragm, a bleed chamber on the opposite side of the diaphragm to the pressure fluid inlet chamber, a bleed passage in the element establishing communication between the pressure fluid inlet chamber and bleed chamber, a passage from the bleed chamber to the pressure fluid exhaust chamber including a Ichamber extending to the lower end of the control head, a master valve operable in the latter chamber to control the last mentioned passage, means controlled by the rise and fall of the liquid in the cylinder to actuate said master valve, and means in line with the last mentioned chamber depending from the control head operatively mounting said master valve.

11. In a pump having a pumping chamber and pneumatic displacement means for admitting liquid into said chamber and forcing liquid therefrom, said pneumatic displacement means including a control head having a passage communieating with the pump chamber so that pressure fluid may be admitted tothe pump chamber and exhausted therefrom, a pressure fluid inlet chamber, a port between the latter chamber and said passage, a pressure fluid exhaust chamber, a port between the latter chamber and passage, a diaphragm in said inlet chamber, valve means to close one port as the other port is opened and vice versa, an element carrying said valve means 0perable by the diaphragm, a bleed chamber on the opposite side of the diaphragm to the pressure fluid inlet chamber, a bleed passage in the element establishing communication between the pressure fluid inlet chamber and bleed chamber, a passage from the bleed chamber to the pressure fluid exhaust chamber, means rising upwardly from the base of the pressure fluid exhaust chamber in continuation of the last mentioned passage to prevent the drainage of deleterious matter into the latter, a master valve in and controlling the last mentioned passage, and means controlled by the rise and fall of the liquid in the cylinder to actuate said master valve.

12. A pump according to claim 11 wherein the last mentioned means is a tube.

13. A pump having a pumping chamber and pneumatic displacement means for admitting liquid into said chamber and forcing liquid therefrom, said pneumatic displacement means including a control head having a passage communicating with the pump chamber so that pressure fluid may be admitted to the pump chamber and exhausted therefrom, a pressure fluid inlet chamber, a port between the latter chamber and said passage, a pressure fluid exhaust chamber, a port between the latter chamber and passage, a diaphragm in said inlet chamber, valve means to close one port as the other port is opened and vice versa, an element carrying said valve means operable by the diaphragm, a removable cap on one side of said diaphragm providing a bleed chamber, a bleed passage in the element establishing communication between the pressure fluid inlet chamber and bleed chamber, a passage extending across the control head from the bleed chamber to the pressure fluid exhaust chamber including a chamber opening at the lower end of the control head, a master valve operable in the latter chamber to control the last mentioned passage, means controlled by the rise and fall of the liquid in the cylinder to actuate said master valve, a cap depending from the control head in line with the last mentioned chamber operatively mounting said master valve, and means rising upwardly from the base of the pressure fluid exhaust chamber in continuation of the last mentioned passage to prevent the drainage of deleterious matter into the latter.

14. A pump according to claim 7 having a loose sleeve on the element protecting the inlet to the bleed passage.

JAMES O. McMlLLAN. 

